Pakistani forces have overrun the Lal Masjid, or Red Mosque, in an upmarket neighbourhood of Islamabad. The rebel cleric, Abdul Rashid Ghazi, who refused to surrender, was shot twice as commandos stormed his basement hideout. At least 58 people are dead and Pakistani troops are dealing with the last pockets of resistance.

How did the siege come about?

The mosque has longstanding links with militancy. The latest trouble began in January when students ranging from young children to people in their 30s occupied a library to protest against the destruction of mosques illegally built on state land.

They later kidnapped women who they claimed were involved in prostitution, abducted police and intimidated shopkeepers selling "obscene" western films, while demanding the enforcement of strict Islamic law, in a Taliban-style campaign.

What brought things to a head?

The final straw may have been the abduction of seven Chinese workers at a massage parlour. They were released within hours, but the incident was a great embarrassment for the president, General Pervez Musharraf. China, an important ally, demanded better security and government troops surrounded the mosque last week.

The official death toll since the confrontation erupted last Tuesday is now put at 71.

Who are the leaders of the movement?

Maulana Abdul Aziz, a preacher famed for his fiery sermons, is the spiritual leader of the Lal Masjid movement, while his brother, Mr Ghazi, is its spokesman. They openly sympathise with al-Qaida and boast of having met Osama bin Laden.

Mr Aziz tried to escape last week, dressed in a burka, but was discovered by a female police officer who was checking women fleeing the mosque.

In a dramatic TV interview Mr Aziz drew back his veil to reveal a bushy beard and told his followers it was time to surrender. Many did leave, but hundreds stayed behind, including Mr Ghazi.

The government has said that up to 450 women and children are being held hostage by a core of about 60 hardened militants leading the fight.

Have there been negotiations?

There have been several rounds of talks. In the latest attempt at a peaceful solution, a delegation of 12 religious leaders headed by the politician Chaudhry Shujaat Hussain started negotiations with Mr Ghazi, initially using a loudspeaker and then a telephone.

Local media reported that Mr Ghazi was prepared to surrender if certain conditions were met, but Gen Musharraf rejected the compromise.

Why did the government storm the mosque?

The safest strategy would have been to starve out the hardcore group remaining in the mosque, but the siege has brought major disruption to the heart of the capital. The area around the building has been cordoned off, impeding traffic and disrupting life for residents.

What are the implications of the crisis?

The pre-dawn raid is a big risk for Gen Musharraf, who has had to weigh the benefits of proving his mettle as an anti-extremist leader against the possible domestic backlash in the event of large-scale casualties.

The president is already in deep political trouble and cuts an increasingly isolated figure following his clumsy attempt to sack Pakistan's chief justice in March. Clashes between government supporters and opposition groups broke out in Karachi in May, leaving 41 people dead. In June the government was forced after international outcry to overturn a decree signed by Gen Musharraf empowering it to close television stations, revoke licences and impose large fines. Gen Musharraf subsequently rounded on his Pakistan Muslim League party for failing to support him, and the mosque siege is only adding to his political troubles.